Backpack



FIG. 1 is a front side elevation view of a backpack showing my new design;

FIG. 2 is a front plan view of the backpack of FIG. 1;

FIG. 3 is a top plan view of the backpack of FIG. 1;

FIG. 4 is bottom plan view of the backpack of FIG. 1;

FIG. 5 is a side plan view of the backpack of FIG. 1;

FIG. 6 is an opposite side plan view of the backpack of FIG. 1;

FIG. 7 is a back plan view of the backpack of FIG. 1;

FIG. 8 is a front side elevation view of a backpack in an open position unzipped position; and,

FIG. 9 is a partial sectional view of an interior of the backpack of FIG. 1.

The broken lines are included for the purpose of illustrating non-claimed subject matter and form no part of the claimed design. 

CLAIM The ornamental design for a backpack, as shown and described. 